Delphi DLL

JSON: Access Array Values

See more JSON Examples

Demonstrates how to access values in a JSON array. Delphi DLL

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, JsonArray, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
json: HCkJsonObject;
jsonStr: PWideChar;
tagsArray: HCkJsonArray;
arraySize: Integer;
i: Integer;
sValue: PWideChar;
iValue: Integer;

begin
success := False;

json := CkJsonObject_Create();

jsonStr := '{ "id": 1, "name": "A green door", "tags": ["home", 22, "green"], "price": 125 }';

success := CkJsonObject_Load(json,jsonStr);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkJsonObject__lastErrorText(json));
    Exit;
  end;

// Get the "tags" array, which contains "home", 22, "green"
tagsArray := CkJsonObject_ArrayOf(json,'tags');
if (CkJsonObject_getLastMethodSuccess(json) = False) then
  begin
    Memo1.Lines.Add('tags member not found.');
    Exit;
  end;

// Get the value at each array index. 
// Output will be:
// [0] = home
// [0] as integer = 0
// [1] = 22
// [1] as integer = 22
// [2] = green
// [2] as integer = 0

arraySize := CkJsonArray_getSize(tagsArray);

for i := 0 to arraySize - 1 do
  begin

    sValue := CkJsonArray__stringAt(tagsArray,i);

    Memo1.Lines.Add('[' + IntToStr(i) + '] = ' + sValue);

    iValue := CkJsonArray_IntAt(tagsArray,i);
    Memo1.Lines.Add('[' + IntToStr(i) + '] as integer = ' + IntToStr(iValue));

  end;

CkJsonArray_Dispose(tagsArray);

// Note: The StringAt method returns the value as a string regardless of the type.

// The IntAt method returns the value as an integer.  If the value does not convert to 
// an integer, then 0 is returned

CkJsonObject_Dispose(json);

end;